1. Field of the Invention
The present invention relates to a connector, a receptacle for connector and a plug for connector, and more specifically relates to a connector comprised of a receptacle and a plug, the receptacle for use in the connector and the plug for use in the connector.
2. Description of the Background Art
In general, a small-sized connector comprised of a receptacle and a plug is provided with an erroneous insertion preventing means for preventing the plug from being inserted into the receptacle in an improper orientation, e.g., in an inverted orientation (Hereinbelow, referred to as “erroneous insertion”).
As an example of such an erroneous insertion preventing means, there is known a method in which a pair of erroneous insertion preventing protrusions are formed below a plug insertion opening of a shield case of the receptacle.
Other known methods include a method in which the top, bottom, left and right portions of a plug shield case and a receptacle shield case are formed asymmetrically, and a method in which the upper corner portions of a plug shield case and the upper corner portions of a receptacle shield case are formed into “C”-shaped surfaces as is the case in a mini-USB connector.
However, the methods mentioned above in turn involve such problems as follows. Namely, in the method in which the erroneous insertion preventing protrusions are provided below the plug insertion opening, the width or height of the receptacle is unavoidably increased in proportion to the size of each protrusion, thus leading to a problem in that it is difficult to further reduce the size of the connector.
Further, in the method in which the upper corner portions of the receptacle shield case and the plug shield case are respectively formed so as to have the “C”-shaped surfaces, no measure is taken to sufficiently cope with the situation that the plug is slantingly inserted into the receptacle. Another problem is that, when the connector is of a smaller size, the plug may sometimes be forcibly inserted into the receptacle in an inverted orientation, despite the provision of such “C”-shaped surfaces.